package com.spzx.product.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.spzx.product.api.domain.SkuLockVo;
import com.spzx.product.domain.SkuStock;
import com.spzx.product.mapper.SkuStockMapper;
import com.spzx.product.service.ISkuStockService;
import com.spzx.product.vo.SkuStockVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.CollectionUtils;

import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

/**
 * <p>
 * 商品sku库存表 服务实现类
 * </p>
 *
 * @author atguigu
 * @since 2024-11-12
 */
@Service
public class SkuStockServiceImpl extends ServiceImpl<SkuStockMapper, SkuStock> implements ISkuStockService {
    @Autowired
    private RedisTemplate redisTemplate;

    @Override
    public SkuStockVo getSkuStock(Long skuId) {
        SkuStock skuStock = baseMapper.selectOne(new LambdaQueryWrapper<SkuStock>()
                .eq(SkuStock::getSkuId, skuId)
                .select(SkuStock::getAvailableNum, SkuStock::getSaleNum));
        SkuStockVo skuStockVo = new SkuStockVo();
        skuStockVo.setSkuId(skuId);
        skuStockVo.setAvailableNum(skuStock.getAvailableNum());
        skuStockVo.setSaleNum(skuStock.getSaleNum());
        return skuStockVo;
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public String checkAndLock(String orderNo, List<SkuLockVo> skuLockVoList) {
        //遍历商品，验库，锁库
        skuLockVoList.forEach(skuLockVo -> {
            SkuStock skuStock = baseMapper.check(skuLockVo.getSkuId(), skuLockVo.getSkuNum());
            if (skuStock == null) {
                skuLockVo.setHaveStock(false);//没有足够库存
            }else {
                skuLockVo.setHaveStock(true);//有足够库存
            }
        });

        //只要有一个商品库存不足
        if (skuLockVoList.stream().anyMatch(skuLockVo -> !skuLockVo.isHaveStock())) {
            //过滤出库存不足的商品
            List<SkuLockVo> noStockList = skuLockVoList.stream()
                    .filter(item -> !item.isHaveStock())
                    .collect(Collectors.toList());

            //组装错误提示
            StringBuffer errorMsg = new StringBuffer();
            for (SkuLockVo skuLockVo : noStockList) {
                //查询现有库存
                Integer availableNum = baseMapper.selectById(skuLockVo.getSkuId()).getAvailableNum();
                errorMsg.append(skuLockVo.getSkuName())
                        .append("库存不足，剩余库存：")
                        .append(availableNum)
                        .append("；");
            }

            //返回错误信息
            return errorMsg.toString();
        }else {//库存充足
            for (SkuLockVo skuLockVo : skuLockVoList) {
                //锁定库存
                baseMapper.lock(skuLockVo.getSkuId(),skuLockVo.getSkuNum());
            }
        }
        // 如果所有商品都锁定成功的情况下，需要缓存锁定信息到redis。以方便将来解锁库存 或者 减库存
        String dataKey = "sku:lock:data:" + orderNo;
        this.redisTemplate.opsForValue().set(dataKey, skuLockVoList);

        return "";
    }

    @Transactional(rollbackFor = {Exception.class})
    @Override
    public void unlock(String orderNo) {
        //幂等性检查
        String key = "sku:unlock:" + orderNo;
        Boolean isFirst = redisTemplate.opsForValue().setIfAbsent(key, orderNo, 1, TimeUnit.HOURS);
        if (!isFirst) return;

        //获取锁定库存的缓存信息
        String dataKey = "sku:lock:data:" + orderNo;
        List<SkuLockVo> skuLockVoList= (List<SkuLockVo>)this.redisTemplate.opsForValue().get(dataKey);

        if (CollectionUtils.isEmpty(skuLockVoList)){
            return;
        }
        //解锁库存
        skuLockVoList.forEach(skuLockVo -> {
            int row = baseMapper.unlock(skuLockVo.getSkuId(), skuLockVo.getSkuNum());
        });
        // 解锁库存之后，删除锁定库存的缓存。
        this.redisTemplate.delete(dataKey);
    }
}
